Knowledge

In hospital operating rooms, ICUs, or emergency rooms, time is life.
When healthcare professionals rush with medical carts loaded with precision instruments
or emergency beds carrying patients, medical casters
become an indispensable and critical component.
When evaluating the performance of medical-grade casters,
"Dynamic Load" and "Static Load" are two figures that not only determine
whether the equipment can glide smoothly, but also directly dictate
the safety of the medical environment. As a professional manufacturer of medical casters,
how does HAION Caster implement these two key indicators into its caster designs?
This article provides an in-depth analysis.
What are Static Load and Dynamic Load?
  1. Static Load
      Static load refers to the maximum weight a caster can withstand when the medical equipment
      is completely stationary and not moving.
      For example, this includes the gravitational pressure exerted on the casters when
      an operating table is locked in a specific position during surgery,
      or when large biochemical analyzer equipment is permanently positioned.
  2. Dynamic Load
      Dynamic load refers to the maximum weight a caster can safely bear
      while the medical equipment is in motion
      (typically associated with a specific speed and obstacles). When a cart moves forward,
      it encounters uneven floors, door thresholds, sudden stops,
      or sharp turns that induce inertia and impact forces.
      Therefore, the testing standards for dynamic load are far more stringent than
      those for static load.
The "Safety Calculation Formula" for Medical Caster Load Capacity
When selecting the right casters for medical equipment,
it is critical to note that you cannot simply divide the total weight of the equipment
by the number of casters to match a single caster's dynamic load rating.
In medical facilities, when a cart is pushed over door thresholds,
elevator gaps, or ward ramps, a "three wheels on the ground, one wheel in the air"
scenario often occurs. At this moment, the entire weight shifts onto three casters.
Furthermore, during a sharp turn,
centrifugal force can even concentrate the weight on just two casters.
To ensure absolute safety, the industry-wide safe load calculation formula is as follows:
                                      
  ◆T = Required dynamic load capacity per single caster
  ◆W1 = Self-weight of the medical equipment (cart/bed)
  ◆W2 = Maximum expected weight of the items/patient loaded on the equipment

Example:
Suppose a medical cart weighs 120 kg, and the medical equipment on it weighs 60 kg,
making the total weight 180 kg.According to the formula:
                                  
Therefore, you should select a HAION Caster with a single-wheel dynamic load
capacity of at least 60 kg to guarantee safe and smooth mobility within medical facilities.
How HAION Caster Tests Dynamic and Static Loads
HAION Casters has become the designated brand for major medical device manufacturers
because every caster model must pass rigorous testing compliant with
international medical caster standards before leaving the factory,
ensuring safety through scientific data:
  1.Static Pressure Test:
     The caster is subjected to continuous load pressure that exceeds its nominal static capacity
     for an extended period. This test checks whether the caster's housing structure undergoes
     any irreversible visual deformation and ensures
     that the tread does not get flat spots under prolonged heavy pressure.
  2.Dynamic Obstacle Test:
     Under simulated fully loaded dynamic conditions,
     the caster is mounted on a dedicated testing machine and run continuously for
     an extended duration. During the test, the caster must repeatedly cross metal obstacles
     of a specific height (simulating ward thresholds and elevator gaps) to ensure
     that the wheel structure, swivel system, and tread remain fully intact under severe impact.